Electric thermostat.



PATENTED DEC. 25, 1906.

M. M. VOGEL E W. J. MEYER.

. ELECTRIC THERMOSTAT.

APPLICATION EILED JULY a, 190e.

Y z?1/'1maoea: i

'UNITED sTATns PATENT orrion,

M AGNUS M. VOGEL AND WILLIAM J. MEYER, OF ALLEGHENY, PENNSYLVANIA.

ELEGTRTC THERMOSTAT.

Specification of Letters Patent.

Patented Dec. 25, 1906.

To a/ZZ whom, it may concern,.-

Be it knownA that we, MAGNUS M. VOGEL and WILLIAM J. MEYER, citizens -of the United States of America, residing at Allegheny, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Electric Thermostats, of which the following is a specification, reference being had therein to the accompanying drawings.

"This invention relates to electric firealarms or thermostats, and particularly to that class of electrical alarms in which an electric circuit is completed to sound an alarm by the expansion by heat of one of the electrodes.

The present invention aims to provide a device of the character indicated of very simple and inexpensive construction in which the parts may be quickly assembled and connected together. I j

The improvement consists of a base or supporting block adapted to be .readily secured against a wall or like support, a strip of expansible sheet metal, means for securing the ends of the metal strip tothe base, and an adjustable contact-point located adjacent to th metal strip, an alarm-bell, and electrical connections for closing a circuit through said bell when the strip expands suliciently4 to contact with said adjustable contact-point.

The construction of the improvement will be yfully described hereinafter in connection with the accompanying drawings, which form part of this specification, and its novel features will be defined in the appended claims.

In the drawings, Figure 1 1s a front elevation of a thermostat constructed in accordance with our'invention. Fig. 2 is a bottom plan view of the same; and Fig. 3 is a section,

a on an enlarged scale, on the line m of Fig. 1.

The reference-numeral 1 designates a block or base, preferably made of cast-1ron although the same may be constructed of other material. An important advantage of employing a cast-iron base is that the securing-lugs for the attachment of the expansible metal strip and the adjustable contactpoint may be formed integral with the block, thus simplifying the construction and reducinfr the cost of manufacture.

clrojecting from the outer surface of the base 1 near each of its upper corners is a lug 2,

said lugs being inclined in opposite directions for the convenient attachment thereto of a strip 3 of copper, brass, or other metal which readily expands by heat. This metallic 'strip'is bent to bow form, as shown, so that its ends will rest against the outer sides of the lugs 2, while its central bowed portion extends adjacent to the lower edge of the base 1 in close proximity to alu 4, projecting from the base ymidway of itsglen th.

The two inclined lugs 2 are provi ed with opeiiings to receive suitable securing-bolts 5, provided with nuts 6 or other suitable securin means extending through corresponding ho es in the ends of the strip 3. The lug 4 is also provided with an opening to receive an adjustable screw 7, the latter being preferably insulated from the lug by means of a bushing 8, of insulating material, and with an electrical conductor 9, leading from one side of a battery, the other, lead 10 from the battery being connected to the one end of the metal strip 3.

-A bell 11 is included in the battery-circuit,

and it will be apparent from the illustration .in the drawings that in case of lire the heat will expand the metal strip 3 and cause it to make electrical contact with the contactpoint 7, thus completing 'a circuit through the bell and sounding the alarm.

By bending the metal strip to bow form the strip is brought to the most advantageous position with relation to the contact-point to insure contact by expansion, and the arrangement of the projecting lugs at opposite incli- 'nations maintains the strip in its bowed position.

We preferably provide the block or base with openings 12 to receive nails or screws for supporting the device upon a wall, and the edges 13 of the block are beveled to impart a finished appearance thereto.

What we claim, and desire to secure by Letters Patent, is-

1. A thermostat comprising' a block or base provided with oppositely-disposed inclined corner-lugs, and a central lug, a bowed strip of expansible material having its ends secured to said inclined lugs, an adjustable contact-point extending through said central lug, and anl electric circuit including an alarm-bell, said contact-point constituting one terminal of the circuit andsaid metal IOO IOS

strip constituting the other terminal, and an electric circuit adapted to be closed by the adapted to expand to contact with Said conexpansion of said strip to sound an alarm.

tact-point to close the circuit.' In testimony whereof we aHiX our signab12-kA tlerrnctat cornprisinlg a cast-linetal tures in the presence of tWo Witnesses. 5 oc or ase avlng integra opposite y-lnclined corner-lugs, and a central lug adjacent Y to the lower edge of the block, a bowed strip of expansible sheet metal secured to said in- Witnesses: clined lugs, an adjustable screw extending MAX H. SROLOVITZ,

1o through said central lug, an alarm-bell, and F O. MCCLEARY. 

